Field of the Invention
The present invention relates to a manufacturing method of a casting, a manufacturing device thereof, and a casting, and particularly, to a manufacturing method of a casting that uses a free casting method, a manufacturing device thereof, and a casting that is manufactured using the free casting method.
Description of the Related Art
Conventionally, a metallic product having a complex form is manufactured by filling melted metal (molten metal) into a mold having a cavity having a predetermined form and solidifying the molten metal in the mold.
Incidentally, with a casting method that uses a mold, it is known that a casting defect such as solidification cracking, shrinkage cavity or porosity, for example, may occur because of restriction and solidification due to cooling from the inner wall surface of the cavity of the mold.
Regarding such a problem, in recent years, techniques regarding casting methods called an upward continuous casting method, a free casting method and the like that do not use a mold have been disclosed in the Related Art cited herein. These casting methods are methods of drawing out molten metal from the bath surface of a molten metal bath storing melted metal (molten metal) along a predetermined path, forming the molten metal drawn out, and solidifying. That is, when molten metal is drawn out from the bath surface of the molten metal bath, the form of the molten metal is temporarily retained by an oxide film formed on its surface or surface tension, and the methods are for forming a casting having a predetermined form by solidifying the molten metal temporarily retained its form using predetermined cooling means after the molten metal drawn out from the molten metal surface, by gradually moving the solidified metal from the bath surface with drawing out new molten metal from the bath surface, and by continuously solidifying the drawn out molten metal.
According to these casting methods, since molten metal drawn out from a molten metal bath can be continuously cooled and solidified, the problem of casting defects such as shrinkage cavities occurring within a mold may be solved, and a high quality casting can be manufactured even in the case of using alloys in which solidification cracking easily occurs, such as 6000 series wrought aluminum alloys, for example.